Systems and methods for slot relation extraction for machine learning task-oriented dialogue systems

ABSTRACT

A system and method for implementing slot-relation extraction for a task-oriented dialogue system that includes implementing dialogue intent classification machine learning models that predict a category of dialogue of a single utterance based on an input of utterance data relating to the single utterance, wherein the category of dialogue informs a selection of slot-filling machine learning models; implementing the slot-filling machine learning models that predict slot classification labels for each of a plurality of slots within the utterance based on the input of the utterance data; implementing a slot relation extraction machine learning model that predicts semantic relationship classifications between two or more distinct slots of tokens of the utterance; and generating a response to the single utterance or performing actions in response to the single utterance based on the semantic relationship classifications between the distinct pairings of the two or more distinct slots of the single utterance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/916,952, filed 18 Oct. 2019, U.S. Provisional Application No.62/990,944, filed 17 Mar. 2020, and U.S. Provisional Application No.63/028,090, filed 21 May 2020, which are incorporated herein theirentireties by this reference.

GOVERNMENT RIGHTS

The subject matter of the invention may be subject to U.S. GovernmentRights under National Science Foundation grants: NSF SBIR Phase 1Grant-1622049 and NSF SBIR Phase 2 Grant-1738441.

TECHNICAL FIELD

The inventions herein relate generally to the machine learning andartificially intelligent dialogue systems fields, and more specificallyto new and useful systems and methods for intelligently implementingmachine learning models of a machine learning-based conversationalservice in the machine learning field.

BACKGROUND

Modern virtual assistants and/or online chatbots may typically beemployed to perform various tasks or services based on an interactionwith a user. Typically, a user interacting with a virtual assistant maypose a question or otherwise submit a command to the virtual assistantto which the virtual assistant may provide a response or a result. Manyof these virtual assistants may be implemented using a rules-basedapproach, which typically requires coding or preprogramming many orhundreds of rules that may govern a manner in which the virtualassistant should operate to respond to a given query or command from auser.

While the rules-based approach for implementing a virtual assistant maybe useful for addressing pointed or specific queries or commands made bya user, the rigid or finite nature of this approach severely limits acapability of a virtual assistant to address queries or commands from auser that exceed the scope of the finite realm of pointed and/orspecific queries or commands that are addressable by the finite set ofrules that drive the response operations of the virtual assistant.

That is, the modern virtual assistants implemented via a rules-basedapproach for generating responses to users may not fully satisfy queriesand commands posed by a user for which there are no predetermined rulesto provide a meaningful response or result to the user.

Additionally, while machine learning enhances capabilities ofartificially intelligent conversational systems, inefficiencies continueto persist in training the underlying machine learning models performingclassification and predictive functions of the artificially intelligentconversation systems.

Therefore, there is a need in the machine learning field for systems andmethods that enable rapid and efficient training of machine learningmodels and for a flexible virtual assistant solution that is capable ofevolving beyond a finite set of rules for effectively and conversantlyinteracting with a user. The embodiments of the present applicationdescribed herein provide technical solutions that address, at least, theneed described above, as well as the deficiencies of the state of theart described throughout the present application.

BRIEF SUMMARY OF THE INVENTION(S)

In one embodiment, a system for implementing slot-relation extraction ina task-oriented dialogue system includes: a natural languageunderstanding (NLU) module implemented by one or more computers of atask-oriented dialogue system, the NLU module comprising: (i) an intentclassification sub-module comprising one or more dialogue intentclassification machine learning models that predict an intent categoryof dialogue of a single utterance based on an input of utterance data,wherein the category of dialogue informs a selection of one or moreslot-filling machine learning models; (ii) a slot-filling sub-modulecomprising the one or more slot-filling machine learning models thatpredict one or more slot classification labels for each of a pluralityof slots within the single utterance; and (iii) a slot relationextraction sub-module comprising a slot relation extraction machinelearning model that predicts one or more semantic relationshipclassifications between distinct pairings of two or more distinct slotsof the single utterance based on an input of the intent category ofdialogue prediction and the one or more slot classification labelpredictions for each of the plurality of slots within the singleutterance; wherein the NLU module identifies one or more semanticrelationships between the distinct pairings of the two or more distinctslots of the single utterance based on the one or more semanticrelationship classification predictions of the slot relation extractionmachine learning model; and a response generator that constructs aresponse to the single utterance or performs one or more actions inresponse to the single utterance based on the one or more semanticrelationships between the distinct pairings of the two or more distinctslots of the single utterance.

In one embodiment, the intent classification sub-module, theslot-filling sub-module, and the slot relation extraction sub-moduletogether define an utterance processing pipeline stage of the NLU model;and the slot filling sub-module is arranged operably downstream, withinthe utterance processing pipeline stage, of the intent classificationsub-module and the slot-filling sub-module.

In one embodiment, the prediction of the semantic relationship betweenthe distinct pairings of the two or more distinct slots of the singleutterance is explicitly predicated on the prediction of the one or moreslot classification labels for each of a plurality of slots within thesingle utterance from the slot-filling sub-module that is arrangedupstream of the slot relation extraction module.

In one embodiment, the one or more slot-filling machine learning modelscomprise one or more light weight slot-filling machine learning modelsthat predict the one or more slot classification labels that informsemantic meaning data of each of the plurality of slots of the singleutterance without informing contextual meaning data of each of theplurality of slots of the single utterance.

In one embodiment, the method includes a training corpus module thatconstructs a training corpus including a plurality of distinctconversational utterance training data samples having slot-wise relationannotations and slot classification annotations, wherein the slot-wiserelation annotations identify a distinct semantic relationship betweeneach pair of slots in the plurality of distinct conversational utterancetraining data samples.

In one embodiment, the method includes a training module that trains theslot relation extraction machine learning model using the trainingcorpus comprising the plurality of distinct conversational utterancetraining data samples having slot-wise relation annotations and slotclassification annotations.

In one embodiment, the response generator compiles into NLU data: (a)the intent category of dialogue; (b) the one or more slot classificationlabels; and (c) the semantic relationship classification betweendistinct pairings of two or more distinct slots of the single utterance;the response generator further constructs the response to the singleutterance or performs the one or more actions in response to the singleutterance based on the NLU data.

In one embodiment, a method for implementing slot-relation extractionfor a task-oriented dialogue system includes: implementing one or moredialogue intent classification machine learning models that predict acategory of dialogue of a single utterance based on an input ofutterance data relating to the single utterance, wherein the category ofdialogue informs a selection of one or more slot-filling machinelearning models; implementing the one or more slot-filling machinelearning models that predict one or more slot classification labels foreach of a plurality of slots within the utterance based on the input ofthe utterance data; implementing a slot relation extraction machinelearning model that predicts one or more semantic relationshipclassifications between two or more distinct slots of tokens of theutterance; and generating a response to the single utterance orperforming one or more actions in response to the single utterance basedon the one or more semantic relationship classifications between thedistinct pairings of the two or more distinct slots of the singleutterance.

In one embodiment, implementing the slot relation extraction machinelearning model includes: identifying all possible pairs of distinctslots based on the plurality of slots of the single utterance; for eachpair of distinct slots, predicting a slot relationship; and annotatingeach of the pair of distinct slots based on the predicted slotrelationship.

In one embodiment, implementing the slot relation extraction machinelearning model is performed synchronously after predictive outputs ofthe one or more dialogue intent classification machine learning modelsand the one or more slot-filling machine learning models.

In one embodiment, implementing the slot relation extraction machinelearning model includes: (i) receiving an input of the prediction of thecategory of dialogue; (ii) receiving an input of the prediction of theone or more slot classification labels; and (iii) generating theprediction of the one or more slot relationship classifications for thesingle utterance based on the prediction of the category of dialogue andthe one or more slot classification labels.

In one embodiment, the method includes constructing a training corpusincluding a plurality of distinct conversational utterance training datasamples having slot-wise relation annotations and slot classificationannotations, wherein the slot-wise relation annotations identify adistinct semantic relationship between each pair of slots in theplurality of distinct conversational utterance training data samples.

In one embodiment, the method includes training the slot relationextraction machine learning model using the training corpus comprisingthe plurality of distinct conversational utterance training data sampleshaving slot-wise relation annotations and slot classificationannotations.

In one embodiment, the one or more slot-filling machine learning modelscomprise one or more light weight slot-filling machine learning modelsthat predict the one or more slot classification labels that informsemantic meaning data of each of the plurality of slots of the singleutterance without informing contextual meaning data of each of theplurality of slots of the single utterance.

In one embodiment, the method includes invoking the slot relationextraction module based on the prediction of the category of dialogue,wherein the invoking includes: referencing a mapping that maps each of aplurality of distinct categories of dialogue to one of a plurality ofdistinct slot relation extraction machine learning models; and selectingthe slot relation extraction machine learning model that is mapped tothe predicted category of dialogue based on the referencing to themapping.

In one embodiment, the slot relation extraction machine learning modelcomprises a slot relation neural network, wherein a structure of theslot relation neural network includes: (a) an embeddings layer, (b) oneor more intermediate layers comprising Bi-LSTMs, (c) a near-terminallayer comprising an attention layer, and (d) a classification layer.

In one embodiment, the utterance data of the single utterance propagatessequentially along the structure of the slot relation neural network byfirst entering the embeddings layer and propagating through one or moreintermediate layers then through the near-terminal layer, and exitingthe classification layer with the one or more semantic relationshipclassifications.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a schematic representation of a system 100 inaccordance with one or more embodiments of the present application;

FIG. 1A illustrates a schematic representation of a variant of system100 that includes slot relation capabilities in accordance with one ormore embodiments of the present application;

FIG. 2 illustrates an example method in accordance with one or moreembodiments of the present application; and

FIG. 3 illustrates a schematic representation of a slot relation neuralnetwork in accordance with one or more embodiments of the presentapplication.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the presentapplication are not intended to limit the inventions to these preferredembodiments, but rather to enable any person skilled in the art to makeand use these inventions.

Overview

As discussed above, existing virtual assistant implementations do nothave the requisite flexibility to address unrecognized queries orcommands from user in which there are no predetermined rules designedaround narrowly defined intents. This inflexible structure cannotreasonably and efficiently address the many variances in the manners inwhich a user may pose a query or command to the virtual assistant.

The embodiments of the present application, however, provide anartificially intelligent machine learning-based dialogue service and/orsystem with natural language processing capabilities that function toprocess and comprehend structured and/or unstructured natural languageinput from a user or input from any other suitable source andcorrespondingly provide highly conversant responses to dialogue inputsto the system. Using one or more trained (deep) machine learning models,such as long short-term memory (LSTM) neural network, the embodiments ofthe present application may function to understand any variety ofnatural language utterance or textual input provided to the system. Theone or more deep machine learning models post deployment can continue totrain using unknown and previously incomprehensible queries or commandsfrom users. As a result, the underlying system that implements the(deep) machine learning models may function to evolve with increasinginteractions with users and training rather than being governed by afixed set of predetermined rules for responding to narrowly definedqueries, as may be accomplished in the current state of the art.

Accordingly, the evolving nature of the artificial intelligence platformdescribed herein therefore enables the artificially intelligent virtualassistant latitude to learn without a need for additional programmingand the capabilities to ingest complex (or uncontemplated) utterancesand text input to provide meaningful and accurate responses.

Additionally, systems and methods are provided that enable anintelligent curation of training data for machine learning models thatenable a rapid and efficient training of machine learning modelsemployed in a machine learning-based dialogue system.

Slot Relation Extraction Overview

Task-oriented dialogue systems may generally combine intentclassification models with slot-filling models as part of their naturallanguage understanding (NLU) module. While intent classification andslot-filling may be able to handle a wide range of queries, they do notalways provide enough information to handle more complex queries thatcontain relationships between slots. Relation Extraction (RE) is theprocess of extracting and classifying semantic information aboutrelationships between two or more items, typically segments of text. REmodels have been to derive structured information from vast amounts ofunstructured text data for various purposes, however the source of thetext data tasks has mainly come from news articles, encyclopediaentries, or blog posts. In one or more embodiments of the presentapplication, systems and methods for applying Relation Extraction modelsto task-oriented dialogue applications are described. In someembodiments, the method includes a novel method for annotating and/orlabeling training sample data. In such embodiments, the method can beused to uncover intelligent insights on (NLU) datasets and may improvethe quality and generalizability of task-driven dialogue systems.

1. System for a Machine Learning-Based Dialogue System

As shown in FIG. 1, a system 100 that implements an artificiallyintelligent virtual assistant includes an artificial intelligence (AI)virtual assistant platform 110 that includes a competency classificationengine 120, a slot identification engine 130, a slot value extractor135, an observables extractor 140, an artificial intelligence virtualassistant response generator 150, and data sources 160. The system 100may additionally include an automatic speech recognition unit 115 and auser interface system 105.

Additionally, as shown in FIG. 1A, a variant schematic of the system 100includes a slot relation extraction module 138. In one or moreembodiments, a variant of the system 100 may integrate a slot relationextraction module 138 after the competency classification (module)engine 120 and slot identification and classification (module) engine130. In such configuration, the slot relation extraction module 138 mayfunction to ingest predictions and/or learnings from the engine 120 andthe engine 130, as input, and further function to compute relationpredictions in an utterance. Accordingly, once the slot relationextraction module 138 produces relation predictions among slots of agiven utterance, slot predictions and relation prediction may beforwarded to one or more back-end applications (e.g., observableextractor 140, response generator 150, etc.).

In one or more embodiments, the competency classification engine 120,the slot classification and identification engine 130 together with theslot relation extraction module 138 may define one or moresub-components of a natural language understanding module (not shown).In such embodiments, each of the engine 120, the engine 130, and theslot relation extraction module 138 may be arranged along a naturallanguage processing pipeline stage in which the slot relation extractionmodule 138 is arranged downstream of the engine 120 and the engine 130.In some embodiments, only after receiving the predictive outputs of theupstream modules does the slot relation extraction module execute onutterance data to predict slot relation data and/or slot relationannotations. Thus, in such embodiments, the predictions of the slotrelation extraction module 138 may be predicated on one or more of thepredictive outputs of the engine 120 and the engine 130. In use, in someembodiments, an implementation of the natural language understandingmodule may be synchronous such that the predictive outputs of thenatural language understanding module propagates synchronously along thepipeline stage.

Additionally, or alternatively, in one or more embodiments, the slotrelation extraction module 138 comprises or implements one or more slotrelation extraction machine learning models. In a preferredimplementation, the one or more slot relation extraction machinelearning models include lightweight slot relation extraction machinelearning models that may function to only extract and/or predictsemantic relationship data between multiple slots and excludepredictions on semantic contextual data. That is, a structure of thelightweight slot relation extraction machine learning models may bemodified and in some cases, reduced in a manner that focuses thepredictive tasks of the model only on classifying slot relationships.

Generally, the system 100 functions to implement the artificialintelligence virtual assistant platform 110 to enable intelligent andconversational responses by an artificially intelligent virtualassistant to a user query and/or user command input into the system 100,as described in U.S. patent application Ser. No. 15/797,414 and U.S.patent application Ser. No. 15/821,010, which are both incorporatedherein in their entireties by this reference. Specifically, the system100 functions to ingest user input in the form of text or speech into auser interface 160. At natural language processing components of thesystem 100 that may include, at least, the competency classificationengine 120 the slot identification engine 130, and a slot valueextractor 135, the system 100 functions to identify a competencyclassification label for the user input data and parse the user inputdata into comprehensible slots or segments that may, in turn, beconverted into program-comprehensible and/or useable features.Leveraging the outputs of the natural language processing components ofthe system 100, the observables extractor 140 may function to generatehandlers based on the outcomes of the natural language processingcomponents and further, execute the generated handlers to therebyperform various operations that accesses one or more data sourcesrelevant to the query or command and that also performs one or moreoperations (e.g., data filtering, data aggregation, and the like) to thedata accessed from the one or more data sources.

The artificial intelligence virtual assistant platform no functions toimplement an artificially intelligent virtual assistant capable ofinteracting and communication with a user. The artificial intelligenceplatform 110 may be implemented via one or more specifically configuredweb or private computing servers (or a distributed computing system;e.g., the cloud) or any suitable system for implementing the system 100and/or the method 200.

In some implementations, the artificial intelligence virtual assistantplatform no may be a remote platform implemented over the web (e.g.,using web servers) that is configured to interact with distinct anddisparate service providers. In such implementation, an event such as auser attempting to access one or more services or data from one or moredata sources of the service provider may trigger an implementation ofthe artificially intelligent virtual assistant of the AI platform no.Thus, the AI virtual assistant platform no may work in conjunction withthe service provider to attend to the one or more queries and/orcommands of the users of the service provider. In this implementation,the data sources 160 may be data sources of the service provider thatare external data sources to the AI virtual assistant platform no.

The competency classification engine 120 together with the slotidentification engine 130 and the slot value extractor 135 preferablyfunction to define a natural language processing (NLP) component of theartificial intelligence platform no. In one implementation, the naturallanguage processing component may additionally include the automaticspeech recognition unit 105.

The competency classification engine 120 functions to implement one ormore competency classification machine learning models to label userinput data comprising a user query or a user command. The one or morecompetency classification machine learning models may include one ormore deep machine learning algorithms (e.g., a recurrent neural network,etc.) that have been specifically trained to identify and/or classify acompetency label for utterance input and/or textual input. The traininginput used in training the one or more deep machine learning algorithmsof the competency classification engine 120 may include crowdsourceddata obtained from one or more disparate user query or user command datasources and/or platforms (e.g., messaging platforms, etc.). However, itshall be noted that the system 100 may obtain training data from anysuitable external data sources. The one or more deep machine learningalgorithms may additionally be continually trained using user queriesand user commands that were miss-predicted or incorrectly analyzed bythe system 100 including the competency classification engine 120.

The competency classification engine 120 may additionally be configuredto generate or identify one competency classification label for eachuser query and/or user command input into the engine 120. The competencyclassification engine 120 may be configured to identify or select from aplurality of predetermined competency classification labels (e.g.,Income, Balance, Spending, Investment, Location, etc.). Each competencyclassification label available to the competency classification engine120 may define a universe of competency-specific functions available tothe system 100 or the artificially intelligent assistant for handling auser query or user command. That is, once a competency classificationlabel is identified for a user query or user command, the system 100 mayuse the competency classification label to restrict one or morecomputer-executable operations (e.g., handlers) and/or filters that maybe used by system components when generating a response to the userquery or user command. The one or more computer-executable operationsand/or filters associated with each of the plurality of competencyclassifications may be different and distinct and thus, may be used toprocess user queries and/or user commands differently as well as used toprocess user data (e.g., transaction data obtained from external datasources 160).

Additionally, the competency classification machine learning model 120may function to implement a single deep machine learning algorithm thathas been trained to identify multiple competency classification labels.Alternatively, the competency classification machine learning model 120may function to implement an ensemble of deep machine learningalgorithms in which each deep machine learning algorithm of the ensemblefunctions to identify a single competency classification label for userinput data. For example, if the competency classification model 120 iscapable of identifying three distinct competency classification labels,such as Income, Balance, and Spending, then the ensemble of deep machinelearning algorithms may include three distinct deep machine learningalgorithms that classify user input data as Income, Balance, andSpending, respectively. While each of the deep machine learningalgorithms that define the ensemble may individually be configured toidentify a specific competency classification label, the combination ofdeep machine learning algorithms may additionally be configured to worktogether to generate individual competency classification labels. Forexample, if the system receives user input data that is determined to behighly complex (e.g., based on a value or computation of the user inputdata exceeding a complexity threshold), the system 100 may function toselectively implement a subset (e.g., three machine learning algorithmsfrom a total of nine machine learning algorithms or the like) of theensemble of machine learning algorithms to generate a competencyclassification label

Additionally, the competency classification engine 120 may beimplemented by the one or more computing servers, computer processors,and the like of the artificial intelligence virtual assistance platform110.

The slot identification engine 130 functions to implement one or moremachine learning models to identify slots or meaningful segments of userqueries or user commands and to assign a slot classification label foreach identified slot. The one or more machine learning modelsimplemented by the slot identification engine 130 may implement one ormore trained deep machine learning algorithms (e.g., recurrent neuralnetworks). The one or more deep machine learning algorithms of the slotidentification engine 130 may be trained in any suitable mannerincluding with sample data of user queries and user commands that havebeen slotted and assigned slot values and/or user system derivedexamples. Alternatively, the slot identification engine 130 may functionto implement an ensemble of deep machine learning algorithms in whicheach deep machine learning algorithm of the ensemble functions toidentify distinct slot labels or slot type labels for user input data.For example, slot identification engine 130 may be capable ofidentifying multiple distinct slot classification labels, such asIncome, Account, and Date labels, then the ensemble of deep machinelearning algorithms may include three distinct deep machine learningalgorithms that function to classify segments or tokens of the userinput data as Income, Account, and Date, respectively.

A slot, as referred to herein, generally relates to a defined segment ofuser input data (e.g., user query or user command) that may include oneor more data elements (e.g., terms, values, characters, media, etc.).Accordingly, the slot identification engine 130 may function todecompose a query or command into defined, essential components thatimplicate meaningful information to be used when generating a responseto the user query or command.

A slot label which may also be referred to herein as a slotclassification label may be generated by the one or more slotclassification deep machine learning models of the engine 130. A slotlabel, as referred to herein, generally relates to one of a plurality ofslot labels that generally describes a slot (or the data elements withinthe slot) of a user query or user command. The slot label may define auniverse or set of machine or program-comprehensible objects that may begenerated for the data elements within an identified slot.

Like the competency classification engine 120, the slot identificationengine 120 may implement a single deep machine learning algorithm or anensemble of deep machine learning algorithms. Additionally, the slotidentification engine 130 may be implemented by the one or morecomputing servers, computer processors, and the like of the artificialintelligence virtual assistance platform no.

The machine learning models and/or the ensemble of machine learningmodels may employ any suitable machine learning including one or moreof: supervised learning (e.g., using logistic regression, using backpropagation neural networks, using random forests, decision trees,etc.), unsupervised learning (e.g., using an Apriori algorithm, usingK-means clustering), semi-supervised learning, reinforcement learning(e.g., using a Q-learning algorithm, using temporal differencelearning), and any other suitable learning style. Each module of theplurality can implement any one or more of: a regression algorithm(e.g., ordinary least squares, logistic regression, stepwise regression,multivariate adaptive regression splines, locally estimated scatterplotsmoothing, etc.), an instance-based method (e.g., k-nearest neighbor,learning vector quantization, self-organizing map, etc.), aregularization method (e.g., ridge regression, least absolute shrinkageand selection operator, elastic net, etc.), a decision tree learningmethod (e.g., classification and regression tree, iterative dichotomiser3, C4.5, chi-squared automatic interaction detection, decision stump,random forest, multivariate adaptive regression splines, gradientboosting machines, etc.), a Bayesian method (e.g., naïve Bayes, averagedone-dependence estimators, Bayesian belief network, etc.), a kernelmethod (e.g., a support vector machine, a radial basis function, alinear discriminate analysis, etc.), a clustering method (e.g., k-meansclustering, expectation maximization, etc.), an associated rule learningalgorithm (e.g., an Apriori algorithm, an Eclat algorithm, etc.), anartificial neural network model (e.g., a Perceptron method, aback-propagation method, a Hopfield network method, a self-organizingmap method, a learning vector quantization method, etc.), a deeplearning algorithm (e.g., a restricted Boltzmann machine, a deep beliefnetwork method, a convolution network method, a stacked auto-encodermethod, etc.), a dimensionality reduction method (e.g., principalcomponent analysis, partial least squares regression, Sammon mapping,multidimensional scaling, projection pursuit, etc.), an ensemble method(e.g., boosting, bootstrapped aggregation, AdaBoost, stackedgeneralization, gradient boosting machine method, random forest method,etc.), and any suitable form of machine learning algorithm. Eachprocessing portion of the system 100 can additionally or alternativelyleverage: a probabilistic module, heuristic module, deterministicmodule, or any other suitable module leveraging any other suitablecomputation method, machine learning method or combination thereof.However, any suitable machine learning approach can otherwise beincorporated in the system 100. Further, any suitable model (e.g.,machine learning, non-machine learning, etc.) can be used inimplementing the artificially intelligent virtual assistant and/or othercomponents of the system 100.

The slot value extraction unit 135 functions to generate slot values byextracting each identified slot and assigned slot label of the userquery or user command and converting the data elements (i.e., slot data)within the slot to a machine or program-comprehensible object orinstance (e.g., term or value); that is, the slot label is mapped tocoding or data that a computer or program of the system 100 comprehendsand is able to manipulate or execute processes on. Accordingly, usingthe slot label generated by the slot identification engine 130, the slotextraction unit 135 identifies a set or group of machine orprogram-comprehensible objects or instances that may be applied to slotdata of a slot assigned with the slot label. Thus, the slot extractionunit 135 may convert the slot data of a slot to a machine orprogram-comprehensible object (e.g., slot values) based on the slotlabel and specifically, based on the available objects, instances, orvalues mapped to or made available under the slot label.

The observables extractor 140 functions to use the slot valuescomprising the one or more program-comprehensible objects generated atslot extraction unit 135 to determine or generate one or more handlersor subroutines for handling the data of or responding to the user queryor user command of user input data. The observables extractor 140 mayfunction to use the slot values provided by the slot extraction unit 135to determine one or more data sources relevant to and for addressing theuser query or the user command and determine one or more filters andfunctions or operations to apply to data accessed or collected from theone or more identified data sources. Thus, the coding or mapping of theslot data, performed by slot extraction unit 135, toprogram-comprehensible objects or values may be used to specificallyidentify the data sources and/or the one or more filters and operationsfor processing the data collected from the data sources.

The response generator 150 functions to use the competencyclassification label of the user input data to identify or select onepredetermined response template or one of a plurality of predeterminedresponse templates. For each competency classification label of thesystem 100, the system 100 may have stored a plurality of responsetemplates that may be selected by the response generator 150 based on anidentified competency classification label for user input data.Additionally, or alternatively, the response template may be selectedbased on both the competency classification label and one or moregenerated slot values. In such instance, the one or more slot values mayfunction to narrow the pool of response template selectable by theresponse generator to a subset of a larger pool of response templates toconsider the variations in a query or user command identified in theslot values. The response templates may generally a combination ofpredetermined output language or text and one or more input slots forinterleaving the handler outputs determined by the observables extractor140.

The user interface system 105 may include any type of device orcombination of devices capable of receiving user input data andpresenting a response to the user input data from the artificiallyintelligent virtual assistant. In some embodiments, the user interfacesystem 105 receives user input data in the form of a verbal utteranceand passes the utterance to the automatic speech recognition unit 115 toconvert the utterance into text. The user interface system 105 mayinclude, but are not limited to, mobile computing devices (e.g., mobilephones, tablets, etc.) having a client application of the system 100,desktop computers or laptops implementing a web browser, an automatedteller machine, virtual and/or personal assistant devices (e.g., Alexa,Google Home, Cortana, Jarvis, etc.), chatbots or workbots, etc. Anintelligent personal assistant device (e.g., Alexa, etc.) may be anytype of device capable of touchless interaction with a user toperforming one or more tasks or operations including providing data orinformation and/or controlling one or more other devices (e.g.,computers, other user interfaces, etc.). Thus, an intelligent personalassistant may be used by a user to perform any portions of the methodsdescribed herein, including the steps and processes of method 200,described below. Additionally, a chatbot or a workbot may include anytype of program (e.g., slack bot, etc.) implemented by one or moredevices that may be used to interact with a user using any type of inputmethod (e.g., verbally, textually, etc.). The chatbot or workbot may beembedded or otherwise placed in operable communication and/or control ofa communication node and thus, capable of performing any process or taskincluding, but not limited to, acquiring and providing information andperforming one or more control operations.

2. Method for Implementing Relation Extraction Methods for DialogueSystems

FIG. 2 shows an exemplary method 200 for implementing relationextraction methods for task-oriented dialogue systems. The method 200,in some embodiments, includes determining, identifying, or classifyingthe dialogue intent or domain (e.g., dialogue competency) of a query orutterance S210, performing slot-filling or entity recognition models toidentify relevant entities in a query S220, and performing a relationextraction step S230. Optionally, the method 200 may include enumeratingpairs of slot segments S231.

In one or more embodiments of the present application, the method 200preferably enables a natural language understanding (NLU) module to morerobustly and generalizability parse and/or understand text or speechinputs or queries containing multiple slots with semantic relations, bymore accurately capturing actionable semantic information. For example,the sentence “Give me three large burgers and two fries” relationsbetween slots (specifically between multiple food items and associatedsizes and quantities). The output of classification and slot-fillingmodels may not be sufficient to correctly handle such queries, andwithout incorporating a relational extraction model step, dialoguesystems may require additional rules written into the back-endapplication to capture and process relations between slots.Implementation of such rules may not be optimal, as they may reduce thegenerality with which the systems may be used, and may introduceunforeseen errors, resulting in a brittle system.

Additionally, or alternatively, the method 200 may also function toenable more scalable deployments of NLU systems with improvements indata annotation and/or labeling schemes that may function to capture anddescribe relations between slots in a training data corpus or corpora.Additionally, such an annotation method may function to enable asimplified slot-filling model in which contextual meaning on a per-slotbasis may be eliminated, enabling the representation of queries aslogical expressions and facilitating more generalizable and scalable NLUsystem development.

2.1 Dialogue Intent Classification

S210, which includes classifying the intent of utterance or query data,may function to determine or identify the scope, domain, class, and/orcategory of dialogue that appropriately describes query or utterancedata, to appropriately classify the type of algorithm or approach thatmay be best suited to answering or responding to the query.

In one or more embodiments, in response to receiving utterance data intoa machine learning-based dialogue system (e.g., system 100), S210 mayfunction to predict one or more competency classifications (labels) orone or more dialogue intent classifications (labels) that mayprobabilistically indicate a category or domain of dialogue intended bya user producing the utterance data, as described in more detail in U.S.patent application Ser. Nos. 15/797,414 and 16/682,081, which areincorporated herein in their entireties by this reference.

In one or more embodiments, performing the dialogue intentclassification task may include implementing one or more trained machinelearning models that may be specifically trained to predict or outputone or more of a plurality of predetermined classification and/orcompetency labels of a machine learning-based dialogue system based onutterance data. In some embodiments, the one or more trained machinelearning models may be implemented using one or more deep machinelearning algorithms and/or using any suitable learning algorithms.

2.2 Slot Filling Task

S220, which includes performing one or more slot-filling operations on agiven query, may function to parse the query or utterance in order toidentify slots, identify appropriate labels for such slots, and filland/or annotate each identified slot with appropriate labels, asdescribed in more detail in U.S. Pat. No. 10,572,801.

In one or more embodiments, S220 may function to perform slot valueidentification of given utterance data that includes identifying detailsin a query or a command to a machine learning-based dialogue system thatenables the system to service the query or the command. In slot valueidentification, S220 may function to segment or parse the query orcommand to identify operative terms that may function cause an executionof one or more actions or operations by the system required forservicing and providing a response to the query or command.

Accordingly, S220 may initially function to decompose an utterance intointelligent (slot) segments, predict one or more slot classificationlabels, annotate each slot with a respective slot classification, andperform one or more operations for responding to the utterance based onthe slot data (i.e., slot classification labels, etc.).

2.3 Relation Extraction Task

S230 invokes one or more of a plurality of distinct slot relation modelsbased on one or both of an utterance intent classification label (S210)and slot-filling values/labels (S220) for a given utterance. In apreferred embodiment, the machine learning-based dialogue systemimplementing the method 200 may include one distinct slot extractionmodel per dialogue intent (i.e., dialogue category, dialogue competency,etc.). Accordingly, in one or more embodiments, the one or morepredictions and/or labels produced in upstream utterance classificationtasks for a given utterance may govern or define which of a plurality ofdistinct slot relation models that may be invoked for predictingrelationships in the given utterance.

In one or more embodiments, to invoke a proper slot relation model, S230may function to reference a mapping of each of a plurality of distinctcompetencies or categories of dialogue of a machine learning-baseddialogue system to one of a plurality of distinct slot relation models.In such embodiment, the mapping may be a coarse mapping in which themapping may be based solely on links between dialogue competency labelsand slot relation models.

In an additional or alternative embodiment, when invoking a proper slotrelation model, S230 may function to reference a granular and/orhierarchical mapping of distinct competencies of dialogue together withslot classification labels to one of a plurality of distinct slotrelation models. In such embodiment, S230 may function to identify asubset of slot relation models from a plurality of distinct slotrelation models and function to identify or select one slot relationmodel from the subset of slot relation models based on one or more slotclassification labels of a given utterance. Accordingly, while S230 mayfunction to use a competency classification label of a given utteranceto identify a top-level or broad category of slot relation models forevaluating the given utterance, S230 may function to subsequently useslot classification labels of he given utterance to identify a tailoredslot relation model best suited for identifying relations between slotsegments of the given utterance.

2.3.1 Slot Pairwise

In one or more embodiments, a single utterance may include multiple slotsegments. In such embodiments, S230 may optionally or additionallyinclude S231, which includes identifying one or more slot segmentpairings for a given utterance. That is, in some embodiments, a givenutterance may include two or more distinct slot segments. Accordingly,S230 includes S231 which may function to enumerate all possible pairs ofslot segments in a subject utterance; each slot segment pairing of theutterance may be treated as an independent relation extraction task.

In such embodiments, S231 may function to create or identify distinctslot segment pairings within a given utterance. For instance, in asubject utterance having three slot segments, S231 may function tocreate or identify up to three distinct slot segment pairings.

In one or more embodiments, S231 may function to duplicate the subjectutterance and emphasize or otherwise, annotate only one distinct slotsegment pairing for evaluation by a selected slot relation model. Inother words, an input to a selected slot relation model may include asubject utterance having a distinct slot segment pairing that may be aprimary subject of a slot relation classification task. In one example,S235 may function to annotate the slot pairings by identifying abeginning and an ending of each of the distinct slot segments of a givenslot segment pairing.

2.3.2 Relation Extraction with Neural Networks

In one or more embodiments, S230 may function to implement a relationextraction machine learning model (sometimes referred to herein as a“relation extraction model”) to identify and/or classify semanticrelations between slot segments of an utterance. In a preferredembodiment, S230 may function to compute or predict whether two or moreslot segments of an utterance have a recognized or emerging relation andfurther, augment the two or more slot segments with slot-wise relationannotations that identifies and/or characterizes a type of relationbetween the two or more slot segments of the utterance.

In a first implementation, a relation extraction model may include asingle machine learning model, such as a single (slot relation) neuralnetwork, having an architecture or structure that includes multipledistinct layers including, at least, an initial layer, one or moreintermediate layers, a near-terminal layer and a terminal layer or oneor more layers subsequent to the intermediate layers. As one example, astructure of the relation extraction model may include an initialembedding layer, one or more intermediate Bi-LSTM layers, and anear-terminal layer comprising an attention layer. It shall be notedthat a structure or composition of the relation extraction model shouldnot be limited to such example, as the relation extraction model mayinclude any number or additional layers including one or more initiallayers, one or more intermediate layers, and/or one or morenear-terminal layers (i.e., one or more layers immediately before theterminal layer) prior to building a prediction or prior to aclassification layer. As such, when a composition of the relationextraction model includes these exemplary layers, an utterance input maypropagate along the neural network sequentially, such that utterancedata travels first to an initial or first layer and is processed andsubsequently to the one or more intermediate layers and lastly to theone or more terminal layers of the relation extraction model.Additionally, or alternatively, in some embodiments, an output of anupstream layer of a relation extraction model may be passed as inputinto a downstream layer of the relation extraction model.

Additionally, or alternatively, in a second implementation, a structureof the relation extraction model may be defined by a composition ofmultiple distinct machine learning models. Thus, in one or moreembodiments, the relation extraction model comprises an ensemble ofmachine learning models whose structure or composition may include, atleast, one or more embedding machine learning models, one or moreBi-LSTM machine learning models, one or more attention layers, and/orany suitable machine learning model. In such embodiment, an utteranceinput being handled by the relation extraction model may be processed inany suitable manner including, but not limited to, a processing ofutterance data asynchronously and/or in parallel by each of the distinctmodels defining the relation extraction ensemble.

2.3.3 Embedding Layer|Vectorization

In one or more embodiments, a slot extraction model may include one ormore language models layers, such one or more embedding layerscomprising word embedding models and/or sentence embedding models. Insuch embodiments, S230 includes S233 which may function to implement theone or more language model layers to encode, categorize, or otherwisegroup words, tokens, or sequences of words or tokens (e.g., phrases orsentences) having similar meanings such that that they have a similarrepresentation.

In a preferred embodiment, a first layer or an early layer of a slotextraction model comprises the one or more embedding models oralgorithms. Accordingly, in such preferred embodiment, utterance data,including a query utterance or the like, may be provided as input to afirst embedding layer at which S233 may function to compute for or mapeach token or slot segment of the utterance data to a wordrepresentation, such as vectors of real numbers or the like.

Additionally, or alternatively, S233 may function to compute anindependent word or sentence representation for each token and/or slotsegment of an utterance and individually pass each word or sentencerepresentation as input into a downstream layer (e.g., a bidirectionalLSTM layer or the like) of a slot extraction model.

S2.3.4 Contextual Semantic Layer

Additionally, or alternatively, in one or more embodiments, the slotrelation extraction model may include an intermediate layer that S230which includes S234 may function to implement to identify or computecontextual semantic data for a given utterance. In a preferredembodiment, the intermediate layer of the slot relation extraction modelincludes a bidirectional LSTM model that may function compute and/oridentify semantic contextual data relating to each slot and/or betweenslot segments of an utterance. In a preferred embodiment, S234 mayfunction to identify dependencies between slots and compute one or morecontext vectors for each of the slot segments of an utterance and/orsummary context vector for an entirety of the utterance.

In one or more embodiments, one or more outputs of a first layer or anupstream layer (e.g., an embedding layer, etc.) of the slot relationextraction model may be passed as input into the intermediate layer. Inone implementation, input into the intermediate layer may include aplurality of distinct word or sentence representations for each of aplurality of distinct slot segments of an utterance. In thisimplementation, S230 may function to include slot pairings data togetherwith the plurality of distinct word or sentence representations. In suchimplementation, the slot pairings data may function to identify which oftwo slot segments of an utterance for which contextual semantic data (orrelation data) may be required and/or define a focus of the intermediatelayer.

It shall be noted that, in the case that an utterance includes multiplepossible slot segment pairings, S234 may function to implement multipleinstances of slot relation extraction model with each distinct instancehaving an input of the same utterance but having distinct slot segmentpairings defining a focus for slot relation data, as shown by way ofexample in FIG. 3. That is, a computational output of the intermediatelayer of the slot relation extraction model should preferably includecontextual semantic data that may be used to inform one or morerelations between the slot segments within the defined slot pairing.

2.3.5 Attention Layer

Additionally, or alternatively, in one or more embodiments, the slotrelation extraction model may include a further intermediate ornear-terminal layer that S230 which includes S235 may function toimplement to identify or predict relative importance of slot segmentsand/or tokens of an utterance to one another. In a preferred embodiment,the near-terminal layer of the slot relation extraction model includesan attention model or an attention mechanism that may function toidentify or determine which slots and/or tokens are more or lessimportant to one another in a given utterance.

In a preferred embodiment, an attention layer of a slot relationextraction model may function to collect, as input, from an upstreamlayer (e.g., BiLSTM layer) of the slot relation extraction contextualsemantic data that may function to identify a potential relationshipbetween at one slot pairing of two distinct segments within a givenutterance. In such embodiment, the attention layer may function tocompute one or more vectors of weights for each distinct slot segmentand/or slot token of a given utterance indicating a relative importanceof each distinct slot segment or token to one another. Preferably, S230computes one or more distinct vectors of weights for a designated slotsegment pairing of the given utterance that preferably identifies arelative importance of a first entity within the slot pairing to thesecond entity and a relative importance of the second entity within theslot pairing to the first entity.

Additionally, or alternatively, the near-terminal layer may use anysuitable algorithm to implement the attention mechanism.

2.3.6 Classification Layer

Additionally, or alternatively, in one or more embodiments, the slotrelation extraction model may include a terminal layer (i.e., aclassification layer) that S230 which includes S236 may function toimplement predict one or more classification labels identifying arelationship between two or more distinct slot segments of a givenutterance.

In one or more embodiments, S236 may function to collect the learningsand/or outputs from one or more of the upstream layers of the slotrelation extraction model. For instance, in some embodiments, embeddingdata, contextual semantic data, and attention data of a given utterancefrom a first layer, an intermediate layer, and a near-terminal layer ofthe slot relation extraction model may be received as input into theclassification layer of the slot relation extraction model.

In a preferred embodiment, the classification layer of the slot relationextraction model comprises a softmax classifier that may function topredict relations between slots of an utterance based on inputs from oneor more upstream layers of the slot relation extraction model. In one ormore embodiments, the machine learning-based dialogue systemimplementing the method 200 may include a plurality of distinctcategories of relation. In such embodiments, a probability output or thelike after an application of a softmax classifier may be mapped to oneof the plurality of distinct categories of relation.

Accordingly, an output of a classification layer of the slot relationextraction model may include an identification of the specific semanticrelations between slots in the dialogue-based utterance.

Additionally, or alternatively, the terminal and/or classification layerof the slot relation extraction model may use any suitable algorithm toimplement the slot relation classification step.

The system and methods of the preferred embodiment and variationsthereof can be embodied and/or implemented at least in part as a machineconfigured to receive a computer-readable medium storingcomputer-readable instructions. The instructions are preferably executedby computer-executable components preferably integrated with the systemand one or more portions of the processors and/or the controllers. Thecomputer-readable medium can be stored on any suitable computer-readablemedia such as RAMs, ROMs, flash memory, EEPROMs, optical devices (CD orDVD), hard drives, floppy drives, or any suitable device. Thecomputer-executable component is preferably a general or applicationspecific processor, but any suitable dedicated hardware orhardware/firmware combination device can alternatively or additionallyexecute the instructions.

Although omitted for conciseness, the preferred embodiments includeevery combination and permutation of the implementations of the systemsand methods described herein.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

What is claimed:
 1. A system for implementing slot-relation extractionin a task-oriented dialogue system, the system comprising: a naturallanguage understanding (NLU) module implemented by one or more computersof a machine learning task-oriented dialogue system, the NLU modulecomprising: (i) an intent classification sub-module comprising one ormore dialogue intent classification machine learning models that predictan intent category of dialogue of a single utterance based on an inputof utterance data, wherein the category of dialogue informs a selectionof one or more slot-filling machine learning models; (ii) a slot-fillingsub-module comprising the one or more slot-filling machine learningmodels that predict one or more slot classification labels for each of aplurality of slots within the single utterance; and (iii) a slotrelation extraction sub-module comprising a slot relation extractionmachine learning model that predicts one or more semantic relationshipclassifications between distinct pairings of two or more distinct slotsof the single utterance based on an input of the intent category ofdialogue prediction and the one or more slot classification labelpredictions for each of the plurality of slots within the singleutterance; wherein the NLU module identifies one or more semanticrelationships between the distinct pairings of the two or more distinctslots of the single utterance based on the one or more semanticrelationship classification predictions of the slot relation extractionmachine learning model; and a response generator that constructs aresponse to the single utterance or performs one or more actions inresponse to the single utterance based on the one or more semanticrelationships between the distinct pairings of the two or more distinctslots of the single utterance.
 2. The system according to claim 1,wherein: the intent classification sub-module, the slot-fillingsub-module, and the slot relation extraction sub-module together definean utterance processing pipeline stage of the NLU model; and the slotfilling sub-module is arranged operably downstream, within the utteranceprocessing pipeline stage, of the intent classification sub-module andthe slot-filling sub-module.
 3. The system according to claim 2, whereinthe prediction of the semantic relationship between the distinctpairings of the two or more distinct slots of the single utterance isexplicitly predicated on the prediction of the one or more slotclassification labels for each of a plurality of slots within the singleutterance from the slot-filling sub-module that is arranged upstream ofthe slot relation extraction module.
 4. The system according to claim 1,wherein the one or more slot-filling machine learning models compriseone or more light weight slot-filling machine learning models thatpredict the one or more slot classification labels that inform semanticmeaning data of each of the plurality of slots of the single utterancewithout informing contextual meaning data of each of the plurality ofslots of the single utterance.
 5. The system according to claim 1,further comprising: a training corpus module that constructs a trainingcorpus including a plurality of distinct conversational utterancetraining data samples having slot-wise relation annotations and slotclassification annotations, wherein the slot-wise relation annotationsidentify a distinct semantic relationship between each pair of slots inthe plurality of distinct conversational utterance training datasamples.
 6. The system according to claim 1, further comprising: atraining module that trains the slot relation extraction machinelearning model using the training corpus comprising the plurality ofdistinct conversational utterance training data samples having slot-wiserelation annotations and slot classification annotations.
 7. The systemaccording to claim 1, wherein the response generator compiles into NLUdata: (a) the intent category of dialogue; (b) the one or more slotclassification labels; and (c) the semantic relationship classificationbetween distinct pairings of two or more distinct slots of the singleutterance; the response generator further constructs the response to thesingle utterance or performs the one or more actions in response to thesingle utterance based on the NLU data.
 8. A method for implementingslot-relation extraction for a task-oriented dialogue system, the methodcomprising: implementing one or more dialogue intent classificationmachine learning models that predict a category of dialogue of a singleutterance based on an input of utterance data relating to the singleutterance, wherein the category of dialogue informs a selection of oneor more slot-filling machine learning models; implementing the one ormore slot-filling machine learning models that predict one or more slotclassification labels for each of a plurality of slots within theutterance based on the input of the utterance data; implementing a slotrelation extraction machine learning model that predicts one or moresemantic relationship classifications between two or more distinct slotsof tokens of the utterance; and generating a response to the singleutterance or performing one or more actions in response to the singleutterance based on the one or more semantic relationship classificationsbetween the distinct pairings of the two or more distinct slots of thesingle utterance.
 9. The method according to claim 8, whereinimplementing the slot relation extraction machine learning modelincludes: identifying all possible pairs of distinct slots based on theplurality of slots of the single utterance; for each pair of distinctslots, predicting a slot relationship; and annotating each of the pairof distinct slots based on the predicted slot relationship.
 10. Themethod according to claim 8, wherein implementing the slot relationextraction machine learning model is performed only after predictiveoutputs of the one or more dialogue intent classification machinelearning models and the one or more slot-filling machine learningmodels.
 11. The method according to claim 10, wherein implementing theslot relation extraction machine learning model includes: (i) receivingan input of the prediction of the category of dialogue; (ii) receivingan input of the prediction of the one or more slot classificationlabels; and (iii) generating the prediction of the one or more slotrelationship classifications for the single utterance based on theprediction of the category of dialogue and the one or more slotclassification labels.
 12. The method according to claim 8, furthercomprising: constructing a training corpus including a plurality ofdistinct conversational utterance training data samples having slot-wiserelation annotations and slot classification annotations, wherein theslot-wise relation annotations identify a distinct semantic relationshipbetween each pair of slots in the plurality of distinct conversationalutterance training data samples.
 13. The method according to claim 12,further comprising: training the slot relation extraction machinelearning model using the training corpus comprising the plurality ofdistinct conversational utterance training data samples having slot-wiserelation annotations and slot classification annotations.
 14. The methodaccording to claim 8, wherein the one or more slot-filling machinelearning models comprise one or more light weight slot-filling machinelearning models that predict the one or more slot classification labelsthat inform semantic meaning data of each of the plurality of slots ofthe single utterance without informing contextual meaning data of eachof the plurality of slots of the single utterance.
 15. The methodaccording to claim 8, further comprising: invoking the slot relationextraction module based on the prediction of the category of dialogue,wherein the invoking includes: referencing a mapping that maps each of aplurality of distinct categories of dialogue to one of a plurality ofdistinct slot relation extraction machine learning models; and selectingthe slot relation extraction machine learning model that is mapped tothe predicted category of dialogue based on the referencing to themapping.
 16. The method according to claim 8, wherein the slot relationextraction machine learning model comprises a slot relation neuralnetwork, wherein a structure of the slot relation neural networkincludes: (a) an embeddings layer, (b) one or more intermediate layerscomprising Bi-LSTMs, (c) a near-terminal layer comprising an attentionlayer, and (d) a classification layer.
 17. The method according to claim16, wherein the utterance data of the single utterance propagatessequentially along the structure of the slot relation neural network byfirst entering the embeddings layer and propagating through one or moreintermediate layers then through the near-terminal layer, and exitingthe classification layer with the one or more semantic relationshipclassifications.